<!DOCTYPE html>
<html lang="zh-CN">
<head>
     <title>03_固定定位</title>
     <style>
        .outer{
            width: 500px;
            background-color: skyblue;
            border: 1px solid black;
            padding: 20px;
        }
        .box{
            width: 200px;
            height: 200px;
            font-size: 20px;
        }

        .box1{
            background-color: #888;
        }
        .box2{
            background-color: orange;
            position: fixed;
            bottom: 0;
            right: 0;
        }
        .box3{
            background-color: green;
        }
     </style>
</head>
<body>
    <div class="outer">
        <div class="box box1">1</div>
        <div class="box box2">2</div>
        <div class="box box3">3</div>
    </div>
</body>
</html>